HI,I have a forum called extreme overclocking that i go to that has a lot of good info,like you say a better CPU would be the easiest and safest way because these take it kinda personal when you mess with their innards.
With info you gave me i will root around on the internet and see whats out there,just changing the CPU is not that hard
you just have be careful when you do,what just thought about while typing this to check and see what a DELL with a 6000+ will do for speed as from what i gathered you can only increase your speed by overclocking about 10%.